Liquid-sealed lifter roof for liquid storage apparatus



Sept. 6, 1949. J. H. WIGGINS 2,481,184

LIQUID-SEALED LIFTER ROOF FOR LIQUID STORAGE APPARATUS Filed April 5, 1946 iinhl:

INVENTOR JOHN H. W/GGIA/s Patented Sept. 6, 1949 EIQUIDSEHED"IIFTER ROOF FORDIQUI-D 'ESTGRAGE APPARATUS JohnH. Wiggins, Chicago, Ill. "Application 'ApriPS, 1946, Serial No. 660,016

roof for saidtarrk, provided' with a skirt, dipr-ing or side wallportion'atrarige'd fin 'tel'esco'pic -relation with :thetank side'iwalL'a/nd a liquidv-seal for said roof, composed of areservoir extending circumferentially around the tank side' 'wall' and containing a liquid sea1ing==medium inwhich the depending side *wall i portion of the roof is immersed.

The main obj'ectvof my present invention 'iSitO provide a fluid *storageapparatus ,of. the1rgeneral type or kind above .menti'onediwhich =is -:of :such design or constructionthat a considerable saving is effected in the 'volume;"or'squantitypf the' liquid used to'seal the'rooflfand-ilossuofthe sealing liquid, due to evaporation'sand/or absonptionwis greatly diminished.

Other objects ':and' desirable 1 matures oi-"my invention will be hereinatterapointed out.

1 I attain the :above described results:

(1) By reducing the width or the-reservoircfor sealing liquid to' a fractional part of-{the {width of the sealing liquidreSeryoir used inia liquid sealed rlifter roof of conventional design;

'(2) By constructingctheiskii't, dip jning :or side wall portion ofthe ,roof in ithe form of a limber,

circumferentially flexible; ningashapedtmember or said side wall portion -iskcalpable'iofea limite 1 circumferential movement relatively {to the :roof,

:and the roof is capablelcfra limited radiator-sidewise movement relative ato saiid'eside Wall por ion, in the event 'lihe'zside :wallistriuctune-Iof the apparatus goes out of round cradle-roof*is subi c fi to wind lpressur'es itending to shift it sidewise or laterally relatively to the stationary tank or container of the apparatus.

Figure 1 of the drawings is a vertical transverse sectional view of a fluid storage apparatus embodying my present invention.

Figure 2 is an enlarged fragmentary vertical sectional view, showing the roof in a raised position.

Figure 3 is a similar view, showing the roof in its lowermost position; and

Figure 4 is a sectional view, taken on the line 4-4 of Figure 2, looking in the direction indicated by the arrows.

In the drawings, A designates the side wall portion of a tank that is:vadapted:toabeuusedrfor storing a fiuid,=u'sually gasoline or tsome other highly volatile material,' B "designatesia'ilifiteriro'of or vertically-movable roof fortsaid:*tarik fildesignates a dependinglside'wall portionnskirtmr dip ring onsaid roof, arranged-instelescopic zrolationship with'the tank :sidexwa'll, iDidesignates :an annular reservoiryherein il'lustrated gas being iattached to the side wall :A of stheitarlk adiafient the top edge of-sameand.proportionedisothai;the annular outer wall of said tescrvoir'duill surround the d-epen'dingrskirt LC onsthe-zl-iqof, 565 3- nates a liquid sealingsmediumeimthe zreservoir such, for example as ;fuel oil in which the'isleirt C is immersed, and E designates ":asanwentirety a roof supportin structure zinsideaof -the"tankiecom posed of a center post that suppontsqa plurality of radially-disposed rafters,"whoseioutereendsgare attached to thetank'side wall :A atzthe top-edge:

of same.

annular member that*has-ilittlezor no cimuinfer-- ential flexibility, and which is rigidly connectecmothe roof, as V has I heretofore Ebeen athe iiniversal. practice, I construct:thecsidewaH hortiQnG-dn the form 'of a cl mber r-ingqor liylinder'ithat"is: circumferentially flexible throughout -.ki.ts fentire area, and I ;suspe nd"=said ;member -from--the: underside of the roof 'iB vby aimeana-ewhich zin addition to maintaining a gasetight joint between.

said parts, makesit possibleqfor the :roof toahave a limited radial movement :or lateralcmovement relatively to the member=C,- :andmakes-impossible.

for said member C to :have a -limited circumieren-- tial movement relatively to the great. the:

preferred formof myginvdntion he d nil llfit afiitfi the means just mentionedacomprises a piulialityiof hangers 1011" links I onuthe iundersidegofwthe roof, connected at their 'upperi-endsby (pivots fi to lugs 3 on the roof,-and connected :at their lower ends by pivots 1 4 -to 211E515 on theexterior' ofutheiside w ll p rti n th an ers 2| "'be ngrs oed-iapa from 6 to 12 ft. around the circumference of the peripheral portion of the roof B. Said means also comprises an annular-shaped, flexible sealing element F, preferably made of gas-tight fabric, attached at it lower end by circumferentially-flexible clamping bars 6 to the top portion of the member C, and attached to its upper end by means of clamping bars 1 to the roof B. The pivotal connections between the links I and the roof B and between said links and the side wall portion C, are loose enough to permit said links to swing radially and also swing slightly to the left and right, as im dicated by broken lines in Figure 4, thereby causing the side wall portion C, in effect, to be floatingly mounted or suspended from the underside of the roof B. Accordingly, in the normal functioning of the apparatus, if there is a tendency for the roof to move sidewise or radially relatively to the side wall A of the tank, or if there is a tendency for the side wall portion C of the roof to move circumferentially relatively to the top portion of the roof, the hangers or links I permit or provide for limited movement of said parts in the directions mentioned. As shown in the drawings, the flexible sealing element F has sufficient slack or fullness to provide for the above mentioned relative movement between the roof B and the side wall portion C, and to prevent the weight of said side wall portion from being imposed on the sealing element.

By constructing the skirt or side wall portion C in the form of a limber, circumferentially flexible member and attaching said member to the roof B in the manner above described, I am able to reduce the width of the reservoir for the sealin liquid from the conventional width of approximately 10 to 14 inches, to approximately 1 inch. Hence, my improved apparatus requires only about to as much sealing liquid as prior liquid-sealed lifter roofs, thereby effecting a considerable saving in the volume or quantity of sealing liquid, and thus reducing the cost of building and maintaining the apparatus. Moreover, as the area of the sealing liquid is only a smal1 fraction of the area of the surface of the sealing liquid in a liquid-sealed lifter roof of conventional design, loss of sealing liquid, due to evaporation and absorption, is greatly diminished. In other words, in my improved apparatus there is only a relatively small body of sealing liquid on the inner side of the side wall portion C of the roof, that can absorb vapors from the material stored in the tank A, because the width of the space between the inner side wall of the reservoir D and the inside face of the depending skirt C of the roof, is usually not more than approximately 1 inch, whereas, in a liquidsealed lifter roof of conventiona1 design, the width of said space is several inches. Also, there is a relatively small body of sealing liquid on the air side, or on the outer side of the skirt C, that is exposed to air, and thus subject to evaporation. In fact, in my improved apparatus the side wall portion or skirt C of the roof and the outer wall of the reservoir D, are preferably so proportioned that when the apparatus is being erected, the skirt is arranged substantially in contact with the inside face of the outer wall of the reservoir D, which outer wall is constructed in the form of a substantially stiff, annular member. If desired, a flexible wiper G can be attached to the top edge of the outer wall of the reservoir D, so as to act on the outer surface of the side wall portion C of the roof, and thus remove from said portion and return to the reservoir, any particles of liquid that adhere to the side wall portion when the roof rises and falls.

As previously stated, a fluid storage apparatus of the construction above described, is an improvement on prior apparatus of the kind equipped with a liquid-sealed lifter roof, in that it requires only a small fractional amount of the sealing liquid employed in prior apparatus, it greatly reduces the loss of sealing liquid resulting from evaporation and/or absorption; and although the sealing liquid reservoir consists of only a narrow trough whose outer wall is in very close relationship with the depending skirt or side wall portion of the roof, the roof can rise and fall and even assume a slightly tilted or angular position, without causing the skirt of the roof to bind in the reservoir, due to the fact that said skirt consists of a circumferentially flexible cylinder that is floatingly suspended from the underside of the roof by a means which comprises a curtain-like, flexible sealing element that maintains a gas-tight joint between the roof and its side Wall portion and at the same time permits said parts to have a limited radial and circumferential movement relatively to each other.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A fluid storage apparatus, comprising a tank having a side wall provided with a reservoir that is adapted to contain a sealing liquid, a verticallymovable roof for said tank, a depending skirt on said roof projecting downwardly into said reservoir, hangers that suspend said skirt from the roof, and a flexible, gas-tight element for sealing the joint between the roof and said skirt, said hangers being constructed so as to permit said skirt to move-circinnferentially a limited distance relatively to the roof.

2. A fluid storage apparatus, comprising a tank having a side wall, a vertically-movable roof for said tank, a skirt projecting downwardly from the roof. a narrow trough .on the side wall of said tank disposed so as to receive said skirt and adopted to contain a sealing liquid, a flexible sealing element for producing a gas-tight joint between the roof and skirt, and a pivotal connection between said skirt and roof.

3. A fluid storage apparatus, comprising a tank having a side wall provided with a reservoir that is adapted to contain a sealing liquid, a verticallymovable roof for said tank, a depending skirt mounted on the underside of the roof by oscillating hangers a flexible sealing element between the roof and skirt, said skirt projecting downwardly into said trough in close proximity to the outer wall of said trough, and a wiper on the outer wall of said trough that bears against the outer surface of said skirt.

JOHN H. WIGGINS.

N 0 references cited. 

